Distinct Roles of GABAergic Interneurons in the Regulation of Striatal Output Pathways

• DOI: 10.1523/jneurosci.4870-09.2010
• Publication Date: 2010-02-10T17:33:24Z
• Authors: Aryn H. Gittis; Alexandra B. Nelson; Myo T. Thwin; Jorge J. Palop; Anatol C. Kreitzer
• Keywords: Interneuron; Medium spiny neuron

Striatal GABAergic microcircuits are critical for motor function, yet their properties remain enigmatic due to difficulties in targeting striatal interneurons electrophysiological analysis. Here, we use Lhx6-GFP transgenic mice identify and investigate regulation of direct- indirect-pathway medium spiny neurons (MSNs). We find that the two major interneuron populations, persistent low-threshold spiking (PLTS) fast (FS) interneurons, differ substantially excitatory inputs inhibitory outputs. Excitatory synaptic currents recorded from PLTS characterized by a small, nonrectifying AMPA receptor-mediated component NMDA component. In contrast, glutamatergic FS have large, strongly rectifying component, but no detectable responses. Consistent with axonal morphology, output individual is relatively weak sparse, whereas robustly connected MSNs other appear mediate bulk feedforward inhibition. Synaptic depression outputs insensitive firing frequency, dynamic-clamp experiments reveal these short-term dynamics enable inhibition efficacious across broad frequency range. Surprisingly, preferentially target direct-pathway over MSNs, suggesting potential mechanism rapid pathway-specific pathways.